feat(store): add thread support to contact model and collector

- Add threadID and threadType to ContactCollector.EnsureContact
- Update ContactStore.UpsertContact signature
- Update Contact type in web UI

internal/store/contact_collector.go

@@ -23,16 +23,17 @@ func NewContactCollector(s ContactStore, c cache.Cache[bool]) *ContactCollector
 }
 
 // EnsureContact creates or refreshes a contact entry, skipping DB if recently seen.
-// contactType: "user" (individual sender) or "group" (group chat entity).
-func (c *ContactCollector) EnsureContact(ctx context.Context, channelType, channelInstance, senderID, userID, displayName, username, peerKind, contactType string) {
-	key := channelType + ":" + senderID
+// contactType: "user" (individual sender), "group" (group chat entity), or "topic" (forum topic).
+// Pass empty threadID/threadType for base contacts (DM, group root).
+func (c *ContactCollector) EnsureContact(ctx context.Context, channelType, channelInstance, senderID, userID, displayName, username, peerKind, contactType, threadID, threadType string) {
+	key := channelType + ":" + senderID + ":" + threadID
 	if _, ok := c.seen.Get(ctx, key); ok {
 		return
 	}
 	if contactType == "" {
 		contactType = "user"
 	}
-	if err := c.store.UpsertContact(ctx, channelType, channelInstance, senderID, userID, displayName, username, peerKind, contactType); err != nil {
+	if err := c.store.UpsertContact(ctx, channelType, channelInstance, senderID, userID, displayName, username, peerKind, contactType, threadID, threadType); err != nil {
 		slog.Warn("contact_collector.upsert_failed", "error", err, "channel", channelType, "sender", senderID)
 		return
 	}

internal/store/contact_store.go

@@ -19,7 +19,9 @@ type ChannelContact struct {
 	Username        *string    `json:"username,omitempty"`
 	AvatarURL       *string    `json:"avatar_url,omitempty"`
 	PeerKind        *string    `json:"peer_kind,omitempty"`
-	ContactType     string     `json:"contact_type"` // "user" or "group"
+	ContactType     string     `json:"contact_type"` // "user", "group", or "topic"
+	ThreadID        *string    `json:"thread_id,omitempty"`
+	ThreadType      *string    `json:"thread_type,omitempty"`
 	MergedID        *uuid.UUID `json:"merged_id,omitempty"`
 	FirstSeenAt     time.Time  `json:"first_seen_at"`
 	LastSeenAt      time.Time  `json:"last_seen_at"`
@@ -37,9 +39,10 @@ type ContactListOpts struct {
 
 // ContactStore manages channel contacts (auto-collected user info).
 type ContactStore interface {
-	// UpsertContact creates or updates a contact. On conflict (channel_type, sender_id),
+	// UpsertContact creates or updates a contact. On conflict (tenant_id, channel_type, sender_id, thread_id),
 	// updates display_name, username, user_id, channel_instance, and last_seen_at.
-	UpsertContact(ctx context.Context, channelType, channelInstance, senderID, userID, displayName, username, peerKind, contactType string) error
+	// Pass empty threadID/threadType for base contacts (DM, group root).
+	UpsertContact(ctx context.Context, channelType, channelInstance, senderID, userID, displayName, username, peerKind, contactType, threadID, threadType string) error
 
 	// ListContacts searches contacts with pagination and filters.
 	ListContacts(ctx context.Context, opts ContactListOpts) ([]ChannelContact, error)

ui/web/src/types/contact.ts

@@ -19,7 +19,9 @@ export interface ChannelContact {
   username?: string;
   avatar_url?: string;
   peer_kind?: string;
-  contact_type: string; // "user" or "group"
+  contact_type: string; // "user", "group", or "topic"
+  thread_id?: string;
+  thread_type?: string;
   merged_id?: string;
   first_seen_at: string;
   last_seen_at: string;